Developer reagents, method of and means for utilizing the same



March 12, 1968 c. s. JOHNSON 3,373,022

DEVELOPER REAGENTS, METHOD OF AND MEANS FOR UTILIZING THE SAME FiledSept. 23, 1965 m N N 0 E s w N H I G J T T O C S E C N M E III! //A R AL C United States Patent 3,373,022 DEVELOPER REAGENTS, METHOD OF ANDMEANS FOR UTILIZING THE SAME Clarence Scott Johnson, 5607 Taliferro St.,Tampa, Fla. 33604 Filed Sept. 23, 1963, Ser. No. 310,728 3 Claims. (Cl.96-439) This invention relates to developer reagents used for thedevelopment of light sensitized prints, as in a blueprint machine andsimilar apparatus, in which the exposed negative is subjected to avaporized developer as distinct from wet processes and contactdevelopment. It will, of course, be understood that certain of the novelfeatures of the herein disclosed developing reagent, as well as themethod steps disclosed, and the apparatus set forth, may have wideapplicability in fields other than the processing of blueprints. Whilethe inventive concept may thus be widely employed, the inventions areherein set forth, by way of example, in connection with present dayconventional multiple print developing machines, it being understoodthat similar reagents, method steps and apparatus for comparableprocesses, may utilize the present fundamental principles.

Blue print machines of the character above referred to conventionallyutilize as a developing medium, vapors produced from ammonium hydroxideNH OH. Conventionally, the liquid ammonium hydroxide is 26 degrees Baurnat 60 degrees Fahrenheit temperature. Such liquid ammonium hydroxide ispumped from a suitable source to an evaporating pan in the machine wherethe liquid is vaporized under suitable heat control to provide theappropriate vapor environment of a vapor chamber above the evaporatingpan to which the exposed print is subjected for development. With suchapparatus, great difiiculty is experienced in maintaining theappropriate and consistent operation of the pump, whereby the iiow ofdeveloper fiuid to the vaporization pan is uniformly synchronized withthe operation of the machine to ensure an adequate yet not excessiveflow of the developer. Further difficulties are experienced in achievingand maintaining an appropriate temperature in the vapor chamber abovethe vaporizing pan and/or the temperature of the liquid wherebyappropriate vaporization takes place. Further, under poorly controlledand hence fluctuating temperature conditions, frequently below theoptimum, the conventional 26 degree Baum NH OH, will not sufiice for theconsistent production of uniformly clear and accurate prints.

The present invention has among its primary objects to provide animproved reagent for use in the conventional vaporizing chamber of thepresent day blueprint machine, or the like, whereby increasedsensitivity of the print is achieved to ensure sharp, accurate andrepeatedly consistant development. The improved reagent of the presentinvention may also include a solvent by which the fixtures for supplyingthe reagent, as well as the vaporizing pan and associated equipment, maybe maintained in a condition free from undue residual deposits ofmaterials which may otherwise deleteriously affect the development. Thereagent of the present invention is also distinguished from thatheretofore used in ice that the ammonium hydroxide may be 27, 28 or 29degrees Baum at 60 degrees Fahrenheit, whereby rapid and consistentevaporation to ensure the adequate vapor content is ensured. The reagentof the present invention is also distinct from the common ammoniumhydroxide now used, in that the hydroxide is subjected to contact withnitrogen gas which may be absorbed in the hydroxide liquid to increasethe speed and efficiency of the developing reaction. The novel apparatusof the present invention includes a pressurized supply of ammonium hydroxide the pressurization of which provides for the flow thereof past amanually adjustable metering valve and through a visual drip gauge,whereby the operator may readily see the rate of flow, and thence underthe applied pressure, to the vaporizing pan. Thus, the arrangement.avoids the use of pumps and the difficulties inherent in the use ofmechanical pumps for supplying the reagent. With respect to suchapparatus, the invention contemplates the use of nitrogen gas as apressurizing fluid over the surface of the ammonium hydroxide, wherebysuch gas not only provides the propulsion required for delivering theliquid to the vaporization pan of the apparatus, but by which thenitrogen may be absorbed to advantageously affect the character of thedeveloping reaction. The method of the present invention, includes thesteps of pressurizing, preferably with nitrogen gas, the surface of theammonium hydroxide for delivering the same through a meter gauge andpast a drip sight gauge to the evaporating pan of a conventionaldeveloping apparatus.

Numerous other objects, features and advantages of the present inventionwill be apparent from a consideration of the following specification,taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a diagrammatic view, illustrating the preferred arrangement ofthe means for supplying a developer reagent to a developing machine, and

FIG. 2 is a fragmentary sectional view illustrating a valved cap for theammonium hydroxide container, whereby ammonium hydroxide of a highdegree Baum may be safely handled and may be controllably fed to thedeveloping machine under gaseous pressure, preferably nitrogen.

Referring now to FIGURE 1 of the drawings, the schematic illustration ofa preferred arrangement for supplying the developing reagent, includes adeveloper container, such as a jar, can, tank, or like receptacle 10 forthe liquid ammonium hydroxide. In the present form of the invention, thecontainer 10 is preferably of 35 lb. bursting strength polyethylene, andis illustrated as having a restricted and externally threaded neck towhich is applied a valved cap 11. For pressurizing the surface of liquiddeveloper reagent within the container 10, there is provided a pressuresupply tube 12, which communicates, preferably under valve control as inFIGURE 2, with the upper area of the container 10. From the cap 11 thetube 12 extends to a gas pressure container 14, preferably underindividual valve control, as indicated at 15. In the preferred form ofthe invention, the pressurizing gas is nitrogen. Under pressure theliquid developer is delivered through a discharge tube 17, preferablyextending well below the normal liquid level of the container andopening at a point adjacent the bottom thereof. From the container 10,the reagent is delivered through the tube 17 to a manually adjustablemetering valve 18 and thence through a visual sight or drip gauge 19 tothe evaporator pan 20 of the developing machine. Thus, the meteringvalve 18 may be set to control the delivery, and the observation of thatdelivery may be made from the sight glass 19, so that by adjusting themetering valve to the speed of operation of the developing machine anadequate supply of liquid developing reagent may be maintained in thepan 20 without use of pumps and the therein attendant problems.

The developing reagent of the present invention, which is to bedelivered to the vaporizing pan of the developing machine, is ammoniumhydroxide, Nl-l O'rI, which may include a solvent and/or have includedtherein, by way of mixture solution, chemical combination or occlusion,free nitrogen. It is of course recognized that 26 degree Baurn ammoniumhydroxide at 60 degrees Fahrenheit has long been recognized as astandard developing reagent to be supplied in liquid form to thevaporizing pan of the developing machine. Since such 26 degree Baumammonium hydroxide has a vaporization point sufiiciently low to besafely handled under normal ambient room temperatures withoutdeleterious effect on the operators, special equipment and sealedcontainers are not required. Under ideal circumstances and operatingconditions of the machine with localized application of heat at theevaporation pan, satisfactory development takes place when thesensitized print is subjected to the vaporized reagent. However, it hasbeen found that consistently superior prints may be secured by the useof ammonium hydroxide of 27, 28, or 29 degrees Baum. Since ammoniumhydroxide of such high Baum is more readily volatilized, lowtemperatures of the evaporation pan and fiuctuation of its temperature,will not preclude adequate development of the print with such ammoniumhydroxide.

The present invention therefore includes as a new developing reagent,ammonium hydroxide of a range from 27 to 29 degrees Baum. Heretofore,such reagent has not been attempted since the higher degree ofvolatilization has precluded free and unhampered use of such material inopen containers. The method of the present invention, however, providesfor the convenient use of closed receptacles which may be sealed in lowtemperature chambers of the distributors of the material, and from whichthey may be delivered sealed, and under valve control for pressurizedclosed circuit delivery to the evaporation pan.

The invention also embraces the use of nitrogen gas as a fortifyingmaterial, which has been found to materially enhance the activities ofthe ammonium hydroxide vapor in its developing effect. Such nitrogen gasmay be introduced into the ammonium hydroxide of 27, 28 or 29 degreesBaum in the cold room of the distributors plant by mechanical mixture,such as by bubbling of the nitrogen gas through the liquid ammoniumhydroxide to form a mixture solution, chemical combination or occlusion.However, it has been found effective for enhancing the developingcharacteristics to merely subject the surface of the ammonium hydroxideto nitrogen gas under pressure in a sealed container. In the presentmethod,

. such nitrogen pressure is also effective as a propulsion means fordelivering the liquid ammonium hydroxide from the sealed container in aclosed circuit to the evaporation pan of the developing apparatus.

- With respect to the addition of nitrogen to the ammonium hydroxide, itis understood that the reagent of the present invention preferablycontemplates the use of an ammonium hydroxide of Baum a degree greaterthan 26. However, it is understood that the invention also embraces theuse of 26 degree Baum ammonium hydroxide which has been subjected tonitrogen gas. Thus, in its broadest aspects, one of the reagents of thepresent invention may be defined as liquid ammonium hydroxide havingbeen subjected to contact with nitrogen gas, and

thus ammonium hydroxide which has mixed, occluded or chemicallyassociated therewith, as by solution or otherwise, additional nitrogen.

The reagent of the present invention also distinguishes from the simple26 degree Baum ammonium hydroxide heretofore used, or ammonium hydroxideof higher Baum degree, by the inclusion of solvent whereby the deliverytubes and the evaporation pan of the developing apparatus are maintainedfree of adhering sediment and may be readily cleaned and/or maintainedin optimum operating condition. The preferred solvent of the presentinvention is an alcohol, preferably a high proof alcohol such asmethanol of 12 degrees Baum. The alcohol may be added to ammoniumhydroxide by mechanical mixture thereto in a proportion of not more thanone part alcohol to 12 parts ammonium hydroxide by volume. Thus, thepresent invention contemplates as a developer reagent, ammoniumhydroxide from 26 to 29 degrees Baum with the addition of the alcoholsolvent in an appropriate proportion. A preferred form of the reagent,however, is an ammonium hydroxide of higher Baum, as from 27 to 29degrees, which includes a solvent. In its more specific form, theinvention contemplates a higher degree Baum ammonium hydroxidecontaining alcohol and nitrogen.

The method step of the present primary inventive concept may be broadlyset forth as including the pressurized delivery of ammonium hydroxide ina closed delivery path from its container to the evaporation pan of thedeveloping machine. More specifically, however, the invention, as to themethod, includes a step of subjecting a high Baum degree ammoniumhydroxide liquid to a surface pressure of nitrogen gas by which theliquid is propelled from the container through a closed circuitincluding a metering valve in a sight gauge and thence to theevaporation pan of a developer.

From the foregoing, it will be seen that the present invention isthreefold, including a new developer reagent of improved reactingqualities with respect to exposed negatives by way of increasedvolatility. A novel feature of the present invention may be the additionof nitrogen and/or a solvent such as alcohol, it being understood thatthe invention as to the reagent, includes the novel use of additionalnitrogen and/or a solvent, though a conventional low degree Baumammonium hydroxide is employed. Secondly, the invention includes a novelapparatus, including a combination of one or more elements such aspressurized container metering pump and sight glass. Thirdly, theinvention includes the method of supplying developer reagent to adeveloper pan by pressurizing the developer supply, and moreparticularly the use of nitrogen gas pressure over the surface ofammonium hydroxide.

It will, of course, be understood that in the practice of the inventionin all of its aspects, as outlined above, numerous changes,modifications and the full use of equivalents may be resorted to withoutdeparture from the spirit or scope thereof as outlined in the appendedclaims.

I claim:

1. The process of developing diazotype reproductions which comprisesexposing the surface of an exposed lightsensitive diazo sheet to thevapor of a developing solution comprising a mixture of an ammoniumhydroxide of a Baum degree above 26 degrees and methanol.

2. The process of developing diazotype reproductions as defined in claim1, wherein the concentration of the ammonium hydroxide in saiddeveloping solution is with* in the range Baum 2729.

3. The process of developing diazotype reproductions as defined in claim1, wherein said solution comprises a mixture of approximately 1 partmethanol to 12 parts ammonium hydroxide.

(References on following page) Mendelsohn 252-153 Eastman 252-153 Breton95-94 Brunk 95-89 Slifkin et al. 252-193 X Colman 96-49 Cross 96-49 XBerger 23-193 Adams et a1. 23-193 Halden 95-94 6 FOREIGN PATENTS 2/1951Great Britain.

OTHER REFERENCES 5 Bennett, H.: The Chemical Formula, vol. 5, Chem.

Pub. Co., 1941, Brooklyn, N.Y., pages 568-571.

Lange, N. A.: Handbook of Chemistry, 7th ed.,

Handbook Pub. Inc., 1949, Sandusky, Ohio, page 1281.

10 J. TRAVIS BROWN, Acting Primary Examiner.

NORMAN G. TORCHIN, Examiner. C. L. BOWERS, Assistant Examiner.

1. THE PROCESS OF DEVELOPING DIAZOTYPE REPRODUCTIONS WHICH COMPRISESEXPOSING THE SURFACE OF AN EXPOSED LIGHTSENSITIVE DIAZO SHEET TO THEVAPOR OF A DEVELOPING SOLUTION COMPRISING A MIXTURE OF AN AMMONIUMHYDROXIDE OF A BAUME DEGREE ABOVE 26 DEGREES AND METHANOL.